Presentation and outcomes of adrenal ganglioneuromas: A cohort study and a systematic review of literature.

OBJECTIVE: To describe the presentation and outcomes of patients with adrenal ganglioneuromas (AGNs). DESIGN: Single-centre retrospective cohort study (1 January 1995 to 31 December 2019) and systematic review of literature (1 January 1980 to 19 November 2019). PATIENTS: Diagnosed with histologically confirmed AGN. MEASUREMENTS: Baseline clinical, imaging and biochemical characteristics, recurrence rates and mortality. Subgroup analysis was performed on tumours with histologic elements of ganglioneuroma and pheochromocytoma (ie composite tumours). RESULTS: The cohort study included 45 patients with AGN, 20 (44%) of which had composite tumours. Compared to pure AGN, patients with composite tumour were older (median age, 62.5 vs. 35 years, p < .001), had smaller tumours (median size, 3.9 vs. 5.7 cm, p = .016) and were discovered incidentally less frequently (65% vs. 84%, p = .009). No recurrences or ganglioneuroma-specific mortality occurred during follow-up (range, 0-266 months). The systematic review included 14 additional studies and 421 patients. The mean age of diagnosis was 39 years, and 47% were women. AGNs were discovered incidentally in 72% of patients, were predominantly unilateral (99%) and had a mean diameter of 5.8 cm and an unenhanced computed tomography (CT) attenuation of -118 to 49 Hounsfield units (HU). On imaging, 69% of AGNs were homogenous, 41% demonstrated calcifications, and 40% were lobulated. CONCLUSIONS: AGNs are rare benign tumours that present with variable imaging features including large size, unenhanced CT attenuation >20 HU, calcifications and lobulated shape. Imaging characteristics can assist in establishing a diagnosis and avoiding an unnecessary adrenalectomy. The association of pheochromocytomas with AGNs is frequent. Diagnosis should include biochemical testing.